1. Field of the Invention
Example embodiments of the present invention relate to manufacturing semiconductor devices, and more particularly, to methods for manufacturing semiconductor devices simultaneously to include low-voltage and high-voltage devices in a single chip.
2. Description of the Related Art
With improvements in integration of semiconductor devices and developments in semiconductor manufacturing technology, attempts have been made to manufacture systems with one-chip semiconductors. Such one-chip semiconductors integrate multiple circuits in a single chip. For example, the circuits that operate a controller and a memory of a system can be integrated in a single chip in order to increase stability in a low-voltage environment.
In order to achieve lightness and integration of a system, a circuit unit which controls a power supply of the system, an input terminal, and an output terminal of the circuit unit can be integrated in a single chip. Since the input terminal and the output terminal are high voltage terminals, it is impossible to structure a general low-voltage transistor circuit including an input terminal and an output terminal. Therefore, currently input and output terminals are structured in high-voltage power transistors. Further, a low-voltage device and a high-voltage device must be separately manufactured when structuring the low-voltage device and the high-voltage device in a single chip. The separate manufacture of low-voltage and high-voltage devices increases the complexity and manufacturing time of the manufacturing process.